I was thinking about this for a few hours and I think you should consider a broader view of communism. Joining a communist party is a specific thing that does not encompass communism as practice. Many of the communist fighters in the 20th century belonged to no party. Many of them never read Marx. Yet they believed in the cause and fought and maybe died for it. The way you write it, it seems that all communists start from reading Marx and then graduating into official party membership. But that doesn’t follow logically or historically.

I guess to summarize a spiral of ideas, I’m fine with calling someone a communist if they are anticapitalist and put that belief into practice in whatever way applies to their own life. If someone lives in the countryside then their path of action is different from an urban worker who can directly engage with their peers for the archetypal “I’m a communist agitating with other communists” lifestyle.